Patents by Inventor Rahim Tafazolli

Rahim Tafazolli has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11606166
    Abstract: Apparatus and methods are disclosed for transmitting and receiving data in a wireless communication network. Apparatus for transmitting data in a wireless communication network comprises a real modulation branch for modulating a first segment of a bit sequence to obtain a real modulated signal, a complex modulation branch for modulating a second segment of the bit sequence to obtain a complex modulated signal, a signal dividing unit configured to divide the bit sequence into a plurality of alternating first segments and second segments, and to send the first segments and the second segments to the real modulation branch and the complex modulation branch respectively, and a transmitter configured to transmit the real and complex modulated signals. Apparatus and methods are also disclosed for demultiplexing a plurality of data streams, using wide linear zero forcing with successive interference cancellation.
    Type: Grant
    Filed: July 7, 2017
    Date of Patent: March 14, 2023
    Assignee: University of Surrey
    Inventors: Juan Carlos De Luna Ducoing, Na Yi, Yi Ma, Rahim Tafazolli
  • Patent number: 11569579
    Abstract: A wireless data transmission apparatus is disclosed, comprising one or more antennas for transmitting data as polarised electromagnetic radiation, and polarisation control means for controlling an axial ratio and a tilt angle of the polarised electromagnetic radiation such that the axial ratio and tilt angle conveys information about the data being transmitted. A corresponding wireless data receiving apparatus is also disclosed. In some embodiments, the one or more antennas comprises a patch antenna, and the polarisation means may comprise a mechanism for varying an electrical length of the angled slot. By utilising the tilt angle and axial ratio of polarised electromagnetic radiation to convey information to the receiver, the spectral efficiency of the system can be increased. A further increase in spectral efficiency may be obtained by using the polarisation control means to modulate first and second carrier waves, and transmitting different data on the first and second carrier waves.
    Type: Grant
    Filed: July 25, 2019
    Date of Patent: January 31, 2023
    Assignee: University of Surrey
    Inventors: Pei Xiao, Timothy Brown, James Kelly, Yasin Kabiri Isfahani, Rahim Tafazolli
  • Publication number: 20220399922
    Abstract: A method and apparatus for transmitting a wireless signal using a beamforming apparatus having a plurality of antennas is disclosed. The technique comprises: generating a first RF signal; and transmitting, using the plurality of antennas, a corresponding plurality of output RF signals to form the transmitted wireless signal; wherein transmitting the plurality of output RF signals comprises, for each antenna: splitting the first RF signal into a pair of second RF signals; shifting a respective phase of each of the pair of second RF signals; adding the phase shifted pair of second RF signals to form a third RF signal; and transmitting, using the antenna, the third RF signal as the corresponding output RF signal for the antenna.
    Type: Application
    Filed: September 10, 2020
    Publication date: December 15, 2022
    Inventors: Sohail Payami, Konstantinos Nikitopoulos, Rahim Tafazolli
  • Publication number: 20210167508
    Abstract: A wireless data transmission apparatus is disclosed, comprising one or more antennas for transmitting data as polarised electromagnetic radiation, and polarisation control means for controlling an axial ratio and a tilt angle of the polarised electromagnetic radiation such that the axial ratio and tilt angle conveys information about the data being transmitted. A corresponding wireless data receiving apparatus is also disclosed. In some embodiments, the one or more antennas comprises a patch antenna, and the polarisation means may comprise a mechanism for varying an electrical length of the angled slot. By utilising the tilt angle and axial ratio of polarised electromagnetic radiation to convey information to the receiver, the spectral efficiency of the system can be increased. A further increase in spectral efficiency may be obtained by using the polarisation control means to modulate first and second carrier waves, and transmitting different data on the first and second carrier waves.
    Type: Application
    Filed: July 25, 2019
    Publication date: June 3, 2021
    Applicant: University of Surrey
    Inventors: Pei XIAO, Timothy BROWN, James KELLY, Yasin KABIRI ISFAHANI, Rahim TAFAZOLLI
  • Publication number: 20200186275
    Abstract: Apparatus and methods are disclosed for transmitting and receiving data in a wireless communication network. Apparatus for transmitting data in a wireless communication network comprises a real modulation branch for modulating a first segment of a bit sequence to obtain a real modulated signal, a complex modulation branch for modulating a second segment of the bit sequence to obtain a complex modulated signal, a signal dividing unit configured to divide the bit sequence into a plurality of alternating first segments and second segments, and to send the first segments and the second segments to the real modulation branch and the complex modulation branch respectively, and a transmitter configured to transmit the real and complex modulated signals. Apparatus and methods are also disclosed for demultiplexing a plurality of data streams, using wide linear zero forcing with successive interference cancellation.
    Type: Application
    Filed: July 7, 2017
    Publication date: June 11, 2020
    Applicant: University of Surrey
    Inventors: Juan Carlos De Luna DUCOING, Na Yi, Yi MA, Rahim TAFAZOLLI
  • Publication number: 20200177302
    Abstract: Apparatus and methods for performing symbol detection on a plurality of mutually interfering information streams transmitted in a wireless communication system are disclosed. The apparatus comprises a detector configured to receive an input signal comprising a plurality of mutually interfering information streams, and to detect a transmitted symbol for one of the plurality of mutually interfering information streams by searching for a vector solution to an optimization problem, and a detection evaluation module configured to classify the detected symbol as reliable or unreliable, and/or to determine whether current system conditions permit reliable symbol detection and to take a predetermined action to improve the detection reliability according to a result of the determination. In some embodiments a decoding algorithm is then applied to the plurality of detected symbols to recover information from said one of the mutually interfering information streams.
    Type: Application
    Filed: August 9, 2018
    Publication date: June 4, 2020
    Applicant: University of Surrey
    Inventors: Konstantinos NIKITOPOULOS, Rahim TAFAZOLLI, Christopher HUSMANN
  • Patent number: 10374841
    Abstract: Apparatus and methods for finding a vector solution to a tree search problem are disclosed. In some embodiments, the apparatus and methods can be used for sphere decoding. The tree search is performed by: obtaining a tree graph; identifying a plurality of nodes in the tree graph that are likely to be part of the solution to the tree graph; partitioning the tree graph into a plurality of sub-trees, each sub-tree including one or more of the identified nodes; processing the plurality of sub-trees in parallel by allocating one or more of the processing elements to each of the sub-trees; and determining the solution based on results of the sub-tree processing.
    Type: Grant
    Filed: June 7, 2016
    Date of Patent: August 6, 2019
    Assignee: UNIVERSITY OF SURREY
    Inventors: Konstantinos Nikitopoulos, Rahim Tafazolli
  • Patent number: 10257678
    Abstract: Data discovery for sensor data in an M2M network uses probabilistic models, such as Gaussian Mixing Models (GMMs) to represent attributes of the sensor data. The parameters of the probabilistic models can be provided to a discovery server (DS) that respond to queries concerning the sensor data. Since the parameters are compressed compared to the attributes of the sensor data itself, this can simplify the distribution of discovery data. A hierarchical arrangement of discovery servers can also be used with multiple levels of discovery servers where higher level discovery servers using more generic probabilistic models.
    Type: Grant
    Filed: May 20, 2015
    Date of Patent: April 9, 2019
    Assignee: Convida Wireless, LLC
    Inventors: Seyed Amir Hoseinitabatabaei, Payam Barnaghi, Lijun Dong, Chonggang Wang, Rahim Tafazolli
  • Publication number: 20180176049
    Abstract: Apparatus and methods for finding a vector solution to a tree search problem are disclosed. In some embodiments, the apparatus and methods can be used for sphere decoding. The tree search is performed by: obtaining a tree graph; identifying a plurality of nodes in the tree graph that are likely to be part of the solution to the tree graph; partitioning the tree graph into a plurality of sub-trees, each sub-tree including one or more of the identified nodes; processing the plurality of sub-trees in parallel by allocating one or more of the processing elements to each of the sub-trees; and determining the solution based on results of the sub-tree processing.
    Type: Application
    Filed: June 7, 2016
    Publication date: June 21, 2018
    Inventors: Konstantinos NIKITOPOULOS, Rahim TAFAZOLLI
  • Patent number: 9706362
    Abstract: A method of determining the location of a device on the body of a user carrying it, comprising determining a mathematical representation of a transformation between a device reference frame and an earth reference frame at the device; receiving information from a sensor arrangement of the device capable of measuring device movement while the user is walking, and transforming information from the sensor arrangement, using said mathematical representation, into the earth reference frame at the device; and performing statistical analysis on at least one component of the information from the sensor arrangement obtained in the transformation to identify one or more features corresponding to a specific location of the device. Also provided is a method of determining the orientation of a user's body relative to a reference frame, using a device carried by a user.
    Type: Grant
    Filed: April 10, 2013
    Date of Patent: July 11, 2017
    Assignee: University of Surrey
    Inventors: Seyed Hoseinitabatabaei, Alexander Gluhak, Rahim Tafazolli
  • Publication number: 20170094592
    Abstract: Data discovery for sensor data in an M2M network uses probabilistic models, such as Gaussian Mixing Models (GMMs) to represent attributes of the sensor data. The parameters of the probabilistic models can be provided to a discovery server (DS) that respond to queries concerning the sensor data. Since the parameters are compressed compared to the attributes of the sensor data itself, this can simplify the distribution of discovery data. A hierarchical arrangement of discovery servers can also be used with multiple levels of discovery servers where higher level discovery servers using more generic probabilistic models.
    Type: Application
    Filed: May 20, 2015
    Publication date: March 30, 2017
    Inventors: Seyed Amir Hoseini TABATABAEI, Payam BARNAGHI, Lijun DONG, Chonggang WANG, Rahim TAFAZOLLI
  • Publication number: 20150072625
    Abstract: A source detection system for detecting wireless communication signals, the system comprising: receiving means for receiving a signal; and processing means arranged to filter the signal to separate it into a plurality of frequency components, determine an energy content for each of the frequency components, calculate a measure of the difference between the energy contents of respective frequency components, and make a determination, from said measure, whether the signal has been transmitted from a source.
    Type: Application
    Filed: April 4, 2012
    Publication date: March 12, 2015
    Applicant: THE UNIVERSITY OF SURREY
    Inventors: Parisa Cheraghi, Yi Ma, Rahim Tafazolli
  • Publication number: 20150065164
    Abstract: A method of determining the location of a device on the body of a user carrying it, comprising determining a mathematical representation of a transformation between a device reference frame and an earth reference frame at the device; receiving information from a sensor arrangement of the device capable of measuring device movement while the user is walking, and transforming information from the sensor arrangement, using said mathematical representation, into the earth reference frame at the device; and performing statistical analysis on at least one component of the information from the sensor arrangement obtained in the transformation to identify one or more features corresponding to a specific location of the device. Also provided is a method of determining the orientation of a user's body relative to a reference frame, using a device carried by a user.
    Type: Application
    Filed: April 10, 2013
    Publication date: March 5, 2015
    Inventors: Seyed Hoseinitabatabaei, Alexander Gluhak, Rahim Tafazolli
  • Patent number: 7787412
    Abstract: A method of obtaining a relative indicator for use in scheduling uplink transmissions from a plurality of source user equipments to a base station is disclosed. The relative indicator indicates the status of a user equipment in comparison to the status of the other user equipments, therefore allowing a user equipment to make more efficient scheduling decisions. The method comprises the steps of determining, for each user equipment, a first indicator which is indicative of a status of that user equipment, determining at least one second indicator from the first indicators obtained for all user equipments and broadcasting the or each second indicator to all user equipments. In this way, a significant reduction the downlink signaling load can be achieved.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: August 31, 2010
    Assignee: Fujistu Limited
    Inventors: Sunil Keshvaji Vadgama, Rahim Tafazolli
  • Patent number: 7707278
    Abstract: A reconfiguration management architecture for a mobile communications system which includes a network and at least one software-definable terminal comprises a configuration management part (10) within the or each terminal and a configuration control part (20). The configuration management part (10) implements a proposed configuration to reconfigure the terminal provided the configuration control part (20) validates the proposed configuration.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: April 27, 2010
    Assignee: University of Surrey
    Inventors: Rahim Tafazolli, Klaus Moessner, Seiamak Vahid
  • Patent number: 7231216
    Abstract: A mobile station positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: June 12, 2007
    Assignee: University of Surrey
    Inventors: Rahim Tafazolli, Shahram Ghaheri-Niri, Jung Houn Yap
  • Publication number: 20060253464
    Abstract: A method for determining the optimum allocation of resources in a mobile telecommunication network. The method includes the step of calculating a fitness parameter for each service class where the fitness parameter is dependent on the quality of service index QoSi, the dynamic queue length q1, and the frequency of resources f1, for each service class.
    Type: Application
    Filed: January 23, 2004
    Publication date: November 9, 2006
    Inventors: Shyamalie Thilakawardana, Rahim Tafazolli
  • Publication number: 20060067275
    Abstract: A method for estimating cell coverage in a mobile telecommunications network. The method includes the steps of receiving signal quality and position information from the users of the network and using the information to calculate a coverage map. Update information is also received to update the coverage map. The estimated cell coverage can be used in radio resource allocation methods.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Applicant: University of Surrey
    Inventors: Xinjie Yang, Rahim Tafazolli
  • Publication number: 20060056346
    Abstract: A method of obtaining a relative indicator for use in scheduling uplink transmissions from a plurality of source user equipments to a base station is disclosed. The relative indicator indicates the status of a user equipment in comparison to the status of the other user equipments, therefore allowing a user equipment to make more efficient scheduling decisions. The method comprises the steps of determining, for each user equipment, a first indicator which is indicative of a status of that user equipment, determining at least one second indicator from the first indicators obtained for all user equipments and broadcasting the or each second indicator to all user equipments. In this way, a significant reduction the downlink signalling load can be achieved.
    Type: Application
    Filed: August 31, 2005
    Publication date: March 16, 2006
    Inventors: Sunil Vadgama, Rahim Tafazolli
  • Publication number: 20050075111
    Abstract: A mobile station positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.
    Type: Application
    Filed: December 5, 2001
    Publication date: April 7, 2005
    Applicant: University of Surrey
    Inventors: Rahim Tafazolli, Shahram Ghaheri-Niri, Jung Yap